1. Field of the Invention
The present invention relates to deck-to-girder connections for precast or prefabricated bridge decks and construction methods thereof, particularly, which allow for structural integration by causing either a bridge deck made from precast concrete (hereinafter, referred to as a “precast concrete deck”) or a bridge deck made from prefabricated fiber reinforced plastic (hereinafter, referred to as a “FRP deck”) to be firmly connected to the girders of a bridge system.
2. Description of the Prior Art
When installing a new precast deck after removal of an existing deck, or installing a new precast deck on new girder bridge, the most common method of structurally connecting the girders with the precast deck is to use what is called a “shear pocket.” The method includes forming or placing the shear pocket in the deck. At least one shear connector is provided on the upper portion of a girder. The precast deck is placed on the upper surface of the girders so that the shear connector is located in the shear pocket. Filling materials such as concrete grout are filled in the shear pocket. As a result, the precast deck is integrally connected to the girders. However, this conventional connection structure has problems as follows:
When connecting the precast deck to the girder system, for example as in building a bridge, there are difficulties as follows. The precast deck is fabricated to have a certain curvature in the transverse and longitudinal directions of the bridge so as to facilitate drainage of the superstructure of the bridge according to the bridge design specifications. By contrast, an upper flange of the girder is fabricated without taking into consideration the curvature of the precast deck as mentioned above. Thus, when the precast deck with a certain curvature is installed on the girder system without any curvature, the installation process must take into consideration whether or not the curvature exists, and then installation is carried out through adjustment of a horizontal position, an elevation, of the precast deck. However, because the precast deck is heavy, it is very difficult to adjust the elevation of the precast deck. Moreover, because this adjustment is completely dependent on a manual work, there is a drawback in that constructability is very poor.
When installing a new precast deck after an existing deck is removed in order to rehabilitate a bridge, there are different difficulties in addition to the forgoing drawback, as follows.
First, since the existing deck, which has been already provided on the girder, is provided as a cast-in-place deck, the existing deck must be removed in order to provide a new deck again. However, after the existing deck is removed, there remain various members, such as shear reinforcing bars, shear connectors, etc., which have been used to connect the existing deck to the girder. Therefore, to install the precast deck, which is formed with a shear pocket, on the existing girder as mentioned above, there is inconvenience in that, after shear connectors, etc., which remain at the girder, are removed, new shear connectors, etc., must be positioned and provided in the shear pocket of the deck.
Second, in the foregoing conventional connection structure using the shear pocket, because the shear pockets have predetermined positions, sizes, numbers, etc., on fabricating the precast deck, there is limitation in that the shear pocket cannot be formed in appropriate correspondence to various situations at a construction site generated during installation.